DE2410226A1 - DEVICE FOR MEASURING THE SPEED OF MOVEMENT OF A CONTINUOUS OBJECT ALONG A PRE-DETERMINED TRAIL - Google Patents

Description

30043 G / Is

Stiftelsen Ins ti tutet - ^e ör mikrovac, -3teknik vid Tekniaka Högskolan, Stockholm / Sweden

Device for measuring the speed of movement of a continuous object along a predetermined trajectory

The invention relates to a device for measuring speed the movement of an icontineal object lengthways a predetermined trajectory. The device has two sensors # which are arranged along the track in good condition and sum generating two signals are suitable, which are im essentially of the same form, al.3r depending on the Äb & tand sv / ischcn the two feelers and the speed of the Movement of said object along said movement path are staggered in time.

Such speed measuring devices are known, for example, from US Pat. No. 3,683,157 and French Pat

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Feelers are connected and serve, on the basis of the SeitK ^ stande3 between the output signals α of the two sensors is the speed, of the <1gen3tandes to calculate.

The object of the invention is to provide such a device which can be used in the textile industry or in other cases in which the speed cat - length of a continuous object made of electrically insulating or non-conductive material, for example a textile thread or yarn, should be measured, which moves along a predetermined orbit. Attempts to use speed measurement devices with magnetic or optical sensors at the speed of textile materials, particularly man-made fibers , have, however, failed for many such materials. Magnetic feelers cannot be varv / ends at all. The signals generated during experiments with optical sensors are often too weak because the cross-sectional areas of the synthetic fiber threads that have been cleaned show only very small changes over their length. It has therefore been found that the known speed measuring devices are not suitable for measuring the speed of, for example, a continuous filament of carbon fiber.

According to the invention, the scope of the measuring device of the general kind indicated in the introduction is also extended to the measurement of the speed of various textile threads, including Cheau fiber thread, by providing the device with sensors having electrodes, cV.e kuts detection of electrostatic charges on a continuous article of electrically insulating material. The Erfi'dnung based on the recognition that swar the physical properties of a continuous article of edektrisch insulating or non-conductive Urteilal on the Ltinge of the object practically constant be kcVmen, the data stored on the surface of the object elektrostatitschen charges, however, usually along de "C

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Show random changes.

The electrodes used in the device according to the invention capture the changes in electrostatic charges the surface of the object by showing the potential of each Electrode changed according to the changes mentioned.

Exemplary embodiments of the invention are illustrated below the attached 2eichnurvj described in more detail. In this shows:

Fi.?. 1 schGinatisoh an embodiment of the inventive concept fioßvor direction with the associated electrical circuit arrangement, rait the two feelers connected to the healing device are;

Fig.2 in a plan view a ^ Maßvorrichtmig, the in addition to two sensing electronics, a common shielding electrode beaitst and

3 shows a modified measuring device with parts of the associated electrical circuit arrangement.

In Pig. 1, a continuous object made of electrically insulating or non-conductive material is denoted by 1. This object consists, for example, of a chemical fiber and is moved in its longitudinal direction over two local supports 15 and 16 . SwaI Klektro.deη are between these supports 15 and 16 arranged * 2 and 3, the transverse er3tsrockt to the object 1 from a one ;; Blechstr "2ifen HA" Tehan. Y> he two electrodes 2 and 3 are arranged at a small distance below the bending path clos Icoütünuierliehen i> egenstannes 1 and in the longitudinal direction at a distance L from one another. The Elektropan 2 and 3 are not available with a preamplifier each. DiG'ic Vor ^ erstärjior beotehen from yes a Feldaffokb-O ^ rAnii 6 bsvf. 7 and '} & 2wei U.tor; rstän <1c-n 4.8 and 5.9, respectively. The / iuijgan

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Each Vox. amplify is prevented with a further amplifier 10 or 11. DiG outputs of the two amplifiers 1O bsi /. 11 are provided with jo an input of a converter 12 connected to a pulse train dnr generated whose pulse frequency of the "c-itabitrncl between Clen don two electrodes i 'and 3 coming 7uisgangssignalen is inversely proportional. For example, the converter of the" in the OS PS 3 Gf5 157 or of the type specified in FR-PS G9 14 146 or PR-PS 71 20 800 no. The output of the converter 12 is provided with a pulse counter 13 which keeps the pulse output from the converter 12. Therefore, the ZühIstarid of the counter 13 int length proportional, has vorbeibevrsgt in 3I, the article 1 to the bpidan sensors 2 and 3. FIG.

If the object 1 is electrical as assumed above insulating material, there are electrical charges on it present in a random distribution noise r its length. Usually electrostatic charges become more sufficient Amount on the surface that Oacmnsf-.andos 1 generates when the Gagenstand from a coil or the like, is bent and if the object moves over different supports, so that additionally «facilities for increasing the amount dor to d-r» r Surface of the object 1 existing charges are usually not required. However, if the normal manipulation charges generated by the object are not sufficient, one can use a device for generating larger charges provide on the item. These bodies can consist of suitable limbs of insulating? "?. Tsrial, which are made by the Item 1 during its movement along the aforementioned Dewbewegungabahn be touched and preferably in the IHhe Measuring device are arranged.

During the * movement of object 1 between the two Supports 15 and 1G change the electrode electrical potential at, dap in jsdon instant from the crowd the electrostatic charge is bostii-imt, which on i.ioin der

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_fc t; »

Electrode 2 adjacent part of the objects 1 are stored. As the charge on the surface changes over the length of the object, the potential of the electrode 2 also changes depending on the distribution of the electrostatic charges along the object 1. The electrode 3 also takes up changing potential at _t that depends on the distribution of charges on the object 1 1εt. The potentials at the two electrodes 2 and 3 therefore change in succession to functions that are similar to one another and which, as a result of the spacing "L between the two electrodes, have a time interval T" from one another, where ν is the speed of movement of the object 1.

It was assumed above that the two electrodes 2 and 3 are located in a small distance below the path of movement of the object 1, so that they are capacitively coupled to it. The electrodes can, however, touch the object 1 mechanically. The two supports 15 and 16 can be made of insulating material. However, you can also use aur. Use electrically conductive material. In this case the supports themselves can form the necessary sensing electrodes.

Xn the preamplifier with one very high input impedance 6 and 7, the output signals of electrodes 2 and 3 are ver ~ strengthens. These preamplifiers can consist of field effect transistors in a common emitter circuit. »The output.« Ignale der Vorver- * become stronger in the normal voltage amplifiers 1o and 11 amplified, whereby signals are generated whose amplitude »is large enough for the time interval 3 measurement in the converter 12. The converter 12 can be comprised of an automatic delay interval measuring device that in one of the aforementioned older patents specified type exist. For example, the converter can generate a pulse train at the pulse frequency Time interval T between two signals is inversely proportional. You can see the total length of the object 1 through the Counters 13 determine, wall the «number of dom converters 12

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-G-

An impulse given to the counter is given to the two Sensors 2 and 3 passed ».» Item 1 directly proportional is.

. The tear device shown in Fig.2 possesses apart from the two. Ftihleluktroden 2 and 3 a geerctofce Ab3chirrcelGktrorie 14, which suppresses the influence of electrostatic charges present in the environment and the capacitive coupling between the two electrodes 2 and 3. Furthermore, this improves the resolution when detecting the electrostatic charges on the object 1, which is particularly useful for achieving a high level of accuracy.

Can lon In the embodiments shown in Figures 1 and 2 Ausführung3beisp ~ e ~ the Filhlelektroden in a printed circuit on a substrate geraainaamen be arranged on a printed shield can optionally be present.

Fig. 3 shows another embodiment in which the sensing electrodes 2 'and 3 * each consist of a pin with a circular cross-section and a shielding electrode 17 or 10 is assigned to each of them. These shielding electrodes are made up of semi-cylindrical shells and are connected to the corresponding preamplifier 6 and 7, respectively, with the dome output de3. Infolgedesrßn follows dna potential teder shield approximately the potential of the. corresponding sensing electrode, so that, on the one hand, capacitive coupling between the remote and sensing electrodes does not significantly reduce the signal level at the sensing electrode, but on the other hand, a shielding against external electrostatic fields is created.

Of course, one can use the measuring device in particular with regard to dor training for Fuhlolöktrodan as part of the Rrfindunw in change various points. For example, the Sensing electrodes consist of a ring that is easier to use Insertion of a thread or the like can be split,

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Claims (1)

P a ten tv η r, η r ü ch e Apparatus for Hoasen the speed of movement of a continuous object lMngs _t a predetermined Dowegungsbahn s. '. It zvoi Y'lihlarn separated from each other along d.er spaced Bex * Egur. "Rsbahn are arranged and-z. /egg. Signals. he can i3ugen * which in w.sentlichen of the same form, but as a function of distance between UEs Αοιλ two sensors and the speed-P zi: Gegonrstander said motion °? lJ: * ngn the above-mentioned Bewagujatj.ibahn z- ^a i + -lieh against inanclor are provided, f 'adur σ h marked that each Imihlcir has an electrode, the ^ un detection of the electrostatic charges on oinoiti continui (.rliehen Gr A situation suitable for that which consists of electrically insulating material and moves along the path of movement 2 »Device according to claim 1, characterized by a Shielding device for the toilvjGi-Ξβη shielding of the electrodes . 409837/0336 Blank page